This invention relates generally to pulse combustion apparatus used as a heat source of hot-water supply apparatus, hot air type heaters or the like, using pulse combustion system having features that combustion takes place with forced intake air and exhaust gasses without a blower while heat conductivity is high.
Generally speaking, the utilization coefficient of thermal energy obtained by combustion in hot-water supply apparatus, hot air type heater or the like is up to 85% at the best, and the improvement of the utilization coefficient to save energy is highly desired.
Conventionally, as measures for improving utilization coefficient various techniques, such as the provision of an auxiliary heat exchanger for recovering heat from exhaust gases, or the utilization of a blower having a large capacity for causing turbulent combustion, have been considered. However, these conventional techniques require a large-capacity auxiliary heat exchanger or result in the occurrence of noise due to the presence of the blower and the turbulent combustion.
Another approach for resolving the above problem is an application of a pulse combination system which was investigated around the time of the oil crisis of 1973, and some apparatus using such pulse combustion is in practical use. However, pulse combustion is based on explosion, and therefore its operating noise level is inherently high. For this reason, it has been desired to decrease the noise level of pulse combustion apparatus although some is already in practical use.